1. Field of the Invention
The invention relates in general to an electronic device and a rotating mechanism thereof, and more particularly to a foldable electronic device and a rotating mechanism thereof.
2. Description of the Related Art
Mobile phone being portable and not subjected to the venue of use has gained great popularity and been widely used. The flip-top mobile phone, which folds the screen to the body of the electronic device, not only reduces the length of the mobile phone but also protects the screen. The flip-top mobile phone is a very popular mobile phone model beloved by many users. The structure of a conventional flip-top mobile phone is elaborated below with accompanied drawings.
Referring to FIG. 1A, an exploded diagram of a conventional mobile phone 100 is shown. The conventional mobile phone 100 using a dual-pivotal structure as a rotating mechanism includes a display casing 110, a host casing 120 and a shaft 130. The display casing 110 is for receiving a display screen. The host casing 120 is for receiving a keypad, a main circuit board and a power. The display casing 110 includes a first protrusion 111 having a first receiving space 111a. The host casing 120 has a second protrusion 122 and a third protrusion 123. The second protrusion 122 has a second receiving space 122a. The third protrusion 123 has a third receiving space 123a. 
The first receiving space 111a is for receiving and enabling the shaft 130 to rotate within. The second receiving space 122a is for receiving one end of the shaft 130 and enabling one end of the shaft 130 to be coupled with the second protrusion 122. The third receiving space 123a is for receiving the other end of the shaft 130 and enabling the other end of the shaft 130 to be coupled with the third protrusion 123.
Referring to FIG. 1B, an assembly diagram of the mobile phone 100 of FIG. 1A is shown. When the shaft 130 placed in the first receiving space 111a is coupled with the second protrusion 122 and the third protrusion 123, the shaft 130 and the second protrusion 122 together form a pivot, and the shaft 130 and the third protrusion 123 form another pivot. The mobile phone 100 uses dual-pivotal structure to clamp the shaft 130 for rotating the display casing 110 and the shaft 130, such that the display casing 110 can be rotated with respect to the host casing 120.
However, the display screen inside the display casing 110 needs to be electrically connected to the main circuit board and the power inside the host casing 120. The display screen is electrically connected to the main circuit board and the power via a flexible circuit board or a flexible wire. The conventional mobile phone 100 is subjected to the shaft 130, the second protrusion 122 and the third protrusion 123, hence making the disposition of the flexible circuit board or the flexible wire relatively difficult.
Moreover, the rotating mechanism of the conventional mobile phone 100 is complicated, and costive moulds are required for forming the first protrusion 111, the second protrusion 122 and the third protrusion 123. Furthermore, the two ends of the shaft 130 must be squeezed in order to be coupled with the second protrusion 122 and the third protrusion 123, making the assembly much more difficult, not only increasing labor hour but also increasing defects. Therefore, how to resolve the above problems has become a focus in the research and development of the semiconductor and related industries.